1. Field of the Invention
The present invention is broadly concerned with improved self-cleaning ovens including an assembly to control the duration of the high-temperature oven cleaning cycles. More particularly, the invention pertains to such ovens, cycle controlling assemblies and methods wherein a parameter of at least a portion of the smoke generated during an oven cleaning cycle is measured and the duration of the cleaning cycle is determined in response to such measurement.
2. Description of the Prior Art
Many household and industrial ovens are equipped with self-cleaning cycles. When an oven is soiled, the user initiates a cleaning cycle, which involves heating of the oven to a very high temperature (e.g., 800.degree. F.) so as to sublimate the oven contaminants. Conventional cleaning cycles operate for a preset period of 2-4 hours so as to insure that all such contaminants are removed from oven surfaces. During the course of a cleaning cycle, smoke is generated as the contaminants char and are sublimated. Usually the period of greatest smoke is during the initial thirty minutes or so of a cycle. Thereafter, smoke production tails off and becomes less prevalent.
A problem with conventional self-cleaning ovens is that the cleaning cycle is conducted for a preset period, regardless of the amount of soil and contaminants in the oven. Thus, the same amount of high temperature operation is carried out for a heavily or lightly soiled oven. This not only unnecessarily takes the oven out of service for longer than may be necessary, but also wastes significant energy.
There is accordingly a need in the art for improved self-cleaning ovens which will terminate an oven cleaning cycle after different periods of heating, in a manner commensurate with the level of soil and contaminants in the oven.